Aobadai about 60 years ago and today

History of Aobadai

Aobadai is in the northwest of Yokohama, where the ridges of the Tama Hills spread out in many branches. It is land where flat surfaces on top of the hills and narrow valleys cutting between them are intricately mixed, and until the railway came it was hills of woods and rice paddies. The photographs can be chosen from six eras, so the hills can be compared step by step on their way to becoming a residential area. The elevation is 37.8 m at the center of the location, 45 m to the east, 30.4 m to the west, 41.9 m to the north and 35.6 m to the south, and the district sits on a surface sloping gently down westward from the eastern ridge.

Paddies tracing the valleys

In the 1961-69 aerial photograph, the whole frame is hills. Ridges covered with dark tree canopy undulate across the frame, and bright bands extend between them while branching. The bands are rice paddies tracing the valley floors, narrowing upstream in the shape of tree branches. The bright bands tracing the valley lines draw the original framework of this land as it was. Narrow roads ride along the backs of the ridges, and hamlets of a few houses each are dotted along the roads. Clusters of roofs can be seen in the lower left and along the bottom edge of the frame, and in the upper right, but all are small and surrounded by fields and woods. Not a single railway runs through this photograph, and no trace of blocks divided by straight lines can be found either.

On the flat surfaces on top of the hills, fields divided into squares are laid out together. In the upper right of the frame especially, the rows of lots are aligned with the direction of the ridge, and you can read how the high surfaces, where water is hard to raise, were used. Paddies in the valleys, fields on the ridges, and woods on the slopes at the boundary: that was the arrangement, and the relief of about 15 m directly became the division of land use.

Urbanization with the station as the axis

In the 1974-78 photograph, the middle of the frame is transformed. A railway line crosses the hills from west-southwest to east-northeast, and slightly left of the center a long, narrow structure and a cluster of large buildings appear. It is the station. In 1966 the Den-en-toshi Line was extended to Nagatsuta and Aobadai Station opened, creating a point where people gather in the middle of the wooded hills. North of the tracks, curving streets following the landform spread out, and toward the left of the frame stand rows of long apartment buildings aligned in the same direction. The south side also has curving streets densely filled with detached houses, but brown undeveloped surfaces and fields are still mixed between them. The order of placing the station first and then building the district can be seen from the shape of the streets and the way the buildings went in. The north and bottom edges of the frame have a different color tone, and those parts are still farmland.

By 1979-83 the difference in color tone has disappeared, and the whole frame becomes one continuous urban area. Around the station, rows of long, narrow buildings and large single roofs have increased, and the station area becomes the center of gravity of the district. Meanwhile, from the upper left to the left edge of the frame, surfaces of bright bare ground with only lot lines drawn remain widely. This is land development in progress. In the upper right a group of fields remains, and in the lower right and along the bottom edge, woods along the valley lines continue in bands. In this photograph it can be read that the wave of urbanization moved west.

A residential area extending west

In the 1984-86 photograph, much of the bare ground that remained on the west side is replaced by roofs. Detached houses are packed between the curving streets, and the rows of long apartment buildings have also grown in number. Even so, brown field surfaces remain at the left edge and in the lower left, and small clusters of woods remain here and there like islands. At the east edge of the frame, fields in long, narrow lots remain in a row, clearly separated from the residential area. The position of this boundary shows that the district was filled in order from the hilltop.

In the 1987-90 photograph, many long, narrow buildings line up around the station, and a band packed with roofs extends east-west along the tracks. On the hills, wide flat surfaces that look like schools and brown sports grounds appear here and there, showing that facilities for daily life have come together in the residential area. Green remains only on the valley floors, on steep parts of the slopes and in groups that look like parks, and the woods of the hills have almost disappeared. At the right edge and in the upper right of the frame, field lots can still be seen.

Green and steps remaining on the hills

In today's photograph, roofs and roads cover the frame without gaps. Many of the valley floors that were paddies in 1961-69 have been replaced by roads and houses, but clusters of round tree canopy remain here and there along the edges of the valleys and as parks, conveying the position of the slopes from the time when they were woods. Around the station the buildings have grown larger, and the band along the tracks has become even denser. A wide road heading southwest from the station side runs diagonally down the hills, with buildings lining both sides without a break. Among the narrow streets branching off like twigs, only this road can be read clearly as a thick line. At the right edge of the frame a wide road runs, with gently curving ramps branching off. In the upper right corner and the lower left corner, straight waterways and field lots remain, showing that farmland continues at the foot of the hills.

For the residential land in Aobadai 1-chome, within the same hills, land values are on record from 1983 up to the 2026 publication. It is 507 m from the location. Starting at 236,000 yen per square meter, it rose sharply to 277,000 yen in 1986 and 475,000 yen in 1987, and reached 785,000 yen in 1988. The peak in values overlaps with the eras of the photographs, and the 1987-90 aerial photograph shows the district at this time. After passing the peak it kept falling, to 520,000 yen in 1993, 400,000 yen in 1996 and 336,000 yen in 2000, and to 285,000 yen in 2004-2005. From there the direction changed: it moved up and down, to 362,000 yen in 2008 and 302,000 yen in 2012, was 351,000 yen in 2020, and is 409,000 yen in the 2026 publication.

Because it is a residential area on hills, the roads wind around to avoid the valleys, and the lots line up with the height changing one step at a time. The boundaries between steps are held by walls and cut vertically. The many slopes and dead ends are the result of the way the lots were divided taking on the shape of the ridges and valleys. The shape of the valleys and ridges remains, transformed into the positions of streets and retaining walls. The places where water collects when it rains also follow the rise and fall of the land. The assumed flood areas and the landslide warning zones are marked on the hazard map published by the city.